Default settings should give a usable cutter mount that's about 20mm taller than djk4linux's orignal design based on his suggestion that a taller mount would probably work better due to putting less lateral force on the needle. So far this seems to be true.
I have a github repo for development on this if anyone wants to colaborate on improving it and/or adding more mount styles. https://github.com/jhitesma/parametric_needle_cutter
8/28/2016 - Finally found time to print one of my own and confirmed that at least with the default settings it works quite well. Original hicwic mount is now included and should work for most reasonable sizes - but the mount isn't parametric yet so it just kind of jumps between two sizes. Also haven't added the new default MPCNC mounts but I'm getting ready to upgrade my MPCNC so will probably add those soon.
Still very much a work in progress. No actual mounts included yet. Not printed yet.
Really only posted so I can get feedback from some people on here: http://forum.flitetest.com/showthread.php?24251-Cutting-foam-sheets-with-a-needle! about how it works as a customizer.
8/17/2016 - Uploaded revised .scad file with hicwic style QC mount and a few minor fixes.
8/17/2016 - Uploaded another revised .scad file fixing some issues with the QC mount. QC mount isn't smart enough to resize yet, but now sits level with the base and will add an extension for taller mounts.